The present invention relates to a power supply module and a power supply unit using such a power supply module.
As for various switching power supplies used for various machine facilities and the like in factories and plants, switching power supplies which have the same output voltage but are different in output W, such as switching power supplies for 15 W, 30 W, 50 W and 100 W, which are different in output W, i.e., power supply capacity, are manufactured and sold at requests, in use, of power supply users.
In the case of switching power supplies having different power supply capacities, however, the size of the casing, arrangement of a circuit board in the casing, the size and arrangement of a transformer and the like differ depending upon the power supply capacity even if the output voltage is the same.
Therefore, power supply manufactures need to newly conduct development and design for every switching power supply which differs in power supply capacity. Since development costs are necessary for every switching power supply which differs in power supply capacity, the sales prices of power supplies are affected.
Furthermore, as for the user as well, when there has occurred the need to use a switching power supply having a power supply capacity different from that used until then according to a load to be used, the user needs to newly purchase a switching power supply having the power supply capacity. Thereupon, the number of switching power supplies to be used increases, and the purchase costs increase.
Therefore, a main object of the present invention is to provide such a power supply module that its power supply capacity can be arbitrarily set by combining a plurality of power supply units.
Another object of the present invention is to provide such a power supply module that it can be used as a power supply having an arbitrary power supply capacity and its power supply manufacturer needs to conduct development design of substantially one power supply unit.
Still another object of the present invention is to provide such a power supply module that its user can set a power supply having a power supply capacity depending upon a load to be used and the necessity for the user to individually purchase power supplies of different capacities can be eliminated.
Other and further objects, features and advantages of the present invention will become apparent from the description below.
In accordance with the present invention, a power supply module includes: a first power supply unit for converting an external AC voltage inputted thereto to a DC voltage, outputting the DC voltage, and supplying the external AC voltage to other power supply units; and one or a plurality of second power supply units for converting an external AC voltage inputted thereto to a DC voltage and outputting the DC voltage, the second power supply units being connected in parallel with the first power supply unit, and an arbitrary power supply capacity is obtained by setting a number of the second power supply units connected in parallel with the first power supply unit.
In accordance with the present invention, preferably both the first power supply unit and the second power supply units can be attached to a DIN rail, and when expanding a power supply capacity, the second power supply unit is attached to the DIN rail and connected in parallel with the first power supply unit.
In accordance with the present invention, preferably the first and second power supply units have an identical power supply capacity.